1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Helper functions for handling target threads/cpus 4 * 5 * Copyright (C) 2012, LG Electronics, Namhyung Kim <namhyung.kim@lge.com> 6 */ 7 8 #include "target.h" 9 10 #include <pwd.h> 11 #include <stdio.h> 12 #include <stdlib.h> 13 #include <string.h> 14 #include <linux/kernel.h> 15 #include <linux/string.h> 16 17 enum target_errno target__validate(struct target *target) 18 { 19 enum target_errno ret = TARGET_ERRNO__SUCCESS; 20 21 if (target->pid) 22 target->tid = target->pid; 23 24 /* CPU and PID are mutually exclusive */ 25 if (target->tid && target->cpu_list) { 26 target->cpu_list = NULL; 27 if (ret == TARGET_ERRNO__SUCCESS) 28 ret = TARGET_ERRNO__PID_OVERRIDE_CPU; 29 } 30 31 /* PID and SYSTEM are mutually exclusive */ 32 if (target->tid && target->system_wide) { 33 target->system_wide = false; 34 if (ret == TARGET_ERRNO__SUCCESS) 35 ret = TARGET_ERRNO__PID_OVERRIDE_SYSTEM; 36 } 37 38 /* BPF and CPU are mutually exclusive */ 39 if (target->bpf_str && target->cpu_list) { 40 target->cpu_list = NULL; 41 if (ret == TARGET_ERRNO__SUCCESS) 42 ret = TARGET_ERRNO__BPF_OVERRIDE_CPU; 43 } 44 45 /* BPF and PID/TID are mutually exclusive */ 46 if (target->bpf_str && target->tid) { 47 target->tid = NULL; 48 if (ret == TARGET_ERRNO__SUCCESS) 49 ret = TARGET_ERRNO__BPF_OVERRIDE_PID; 50 } 51 52 /* BPF and THREADS are mutually exclusive */ 53 if (target->bpf_str && target->per_thread) { 54 target->per_thread = false; 55 if (ret == TARGET_ERRNO__SUCCESS) 56 ret = TARGET_ERRNO__BPF_OVERRIDE_THREAD; 57 } 58 59 /* THREAD and SYSTEM/CPU are mutually exclusive */ 60 if (target->per_thread && (target->system_wide || target->cpu_list)) { 61 target->per_thread = false; 62 if (ret == TARGET_ERRNO__SUCCESS) 63 ret = TARGET_ERRNO__SYSTEM_OVERRIDE_THREAD; 64 } 65 66 return ret; 67 } 68 69 uid_t parse_uid(const char *str) 70 { 71 struct passwd pwd, *result; 72 char buf[1024]; 73 74 if (str == NULL) 75 return UINT_MAX; 76 77 /* Try user name first */ 78 getpwnam_r(str, &pwd, buf, sizeof(buf), &result); 79 80 if (result == NULL) { 81 /* 82 * The user name not found. Maybe it's a UID number. 83 */ 84 char *endptr; 85 int uid = strtol(str, &endptr, 10); 86 87 if (*endptr != '\0') 88 return UINT_MAX; 89 90 getpwuid_r(uid, &pwd, buf, sizeof(buf), &result); 91 92 if (result == NULL) 93 return UINT_MAX; 94 } 95 96 return result->pw_uid; 97 } 98 99 /* 100 * This must have a same ordering as the enum target_errno. 101 */ 102 static const char *target__error_str[] = { 103 "PID/TID switch overriding CPU", 104 "PID/TID switch overriding SYSTEM", 105 "SYSTEM/CPU switch overriding PER-THREAD", 106 "BPF switch overriding CPU", 107 "BPF switch overriding PID/TID", 108 "BPF switch overriding THREAD", 109 }; 110 111 int target__strerror(struct target *target __maybe_unused, int errnum, 112 char *buf, size_t buflen) 113 { 114 int idx; 115 const char *msg; 116 117 BUG_ON(buflen == 0); 118 119 if (errnum >= 0) { 120 str_error_r(errnum, buf, buflen); 121 return 0; 122 } 123 124 if (errnum < __TARGET_ERRNO__START || errnum >= __TARGET_ERRNO__END) 125 return -1; 126 127 idx = errnum - __TARGET_ERRNO__START; 128 msg = target__error_str[idx]; 129 130 switch (errnum) { 131 case TARGET_ERRNO__PID_OVERRIDE_CPU ... 132 TARGET_ERRNO__BPF_OVERRIDE_THREAD: 133 snprintf(buf, buflen, "%s", msg); 134 break; 135 136 default: 137 /* cannot reach here */ 138 break; 139 } 140 141 return 0; 142 } 143